dovecot 2.4 config

Minimal docker setup for testing dovecot 2.4 configurations.

This repo provides a few example setups for running with the official Dovecot Docker image.

If you are having difficulty upgrading your config to 2.4.x from a previous version of Dovecot, follow the instructions here to debug your upgraded settings.

The basic procedure is to run the config, run and test steps adding in your configuration piece-by-piece to check your new configuration works.

Warning

The dovecot.conf file provided here is insecure.

Contents

• config
• run
• test
• examples
• notes

config

Grab the minimal dovecot.conf and users.db here or in one of the example directories and invoke docker run.

To modify variables from the Dovecot 2.3 or earlier config please read the 2.4 variables docs. and upgrade documentation.

run

An example docker invocation, with configuration loaded from the current directory, which also holds the users.db file provided here:

docker run -p 1143:143 -p 1993:993 \
           -v ./:/etc/dovecot \
              dovecot/dovecot:latest

test

Example login with no domain, using auth_default_domain

$ nc 127.0.0.1 1143
* OK [CAPABILITY IMAP4rev1 LOGIN-REFERRALS ID ENABLE IDLE SASL-IR
  LITERAL+ AUTH=PLAIN] Dovecot ready.
a login tom test
a OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT
  ...trimmed...
  Logged in

Example login with specified domain:

$ nc 127.0.0.1 1143
* OK [CAPABILITY IMAP4rev1 LOGIN-REFERRALS ID ENABLE IDLE SASL-IR
  LITERAL+ AUTH=PLAIN] Dovecot ready.
a login terry@another.com test
a OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT
  ...trimmed...
  Logged in

The dovecot config provided here logs to /dev/stderr, and produces output along the lines below. Note the expansion to tom@example.com.

Aug 15 17:05:53 master: Info: Dovecot v2.4.1 (7d8c0e5759) starting up for imap
Aug 15 17:05:57 auth: Debug: Loading modules from directory: /dovecot/lib/dovecot/modules/auth
...
Aug 15 17:05:57 auth: Debug: Wrote new auth token secret to /run/dovecot/auth-token-secret.dat
Aug 15 17:05:57 auth: Debug: passwd-file /etc/dovecot/users.db:Read 3 users in 0 secs
...
Aug 15 17:06:02 auth: Debug: conn unix:login (pid=12,uid=1000) [1]: client in: AUTH	1	PLAIN	protocol=imap	final-resp-ok	session=Cd5NZ2o8ZpysEQAB	lip=172.17.0.2	rip=172.17.0.1	lport=143	rport=40038	resp=<hidden>
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: Performing passdb lookup
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: lookup: user=tom@example.com file=/etc/dovecot/users.db
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: Finished passdb lookup
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: Auth request finished
Aug 15 17:06:02 auth: Debug: conn unix:login (pid=12,uid=1000) [1]: client passdb out: OK	1	user=tom@example.com	:=	original_user=tom
Aug 15 17:06:02 auth: Debug: conn unix:/run/dovecot/auth-master (pid=15,uid=1000): Server accepted connection (fd=20)
Aug 15 17:06:02 auth: Debug: master in: REQUEST	3342336001	12	1	c32446853f20868faf73f76a286beab0	session_pid=15	request_auth_token
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: Performing userdb lookup
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: lookup: user=tom@example.com file=/etc/dovecot/users.db
Aug 15 17:06:02 auth(tom@example.com,172.17.0.1,sasl:plain)<Cd5NZ2o8ZpysEQAB>: Debug: passwd-file: Finished userdb lookup
Aug 15 17:06:02 auth: Debug: master userdb out: USER	3342336001	tom@example.com	uid=1000	gid=1000	home=/srv/mail/tom	auth_mech=PLAIN	auth_token=1da9be7cba83819ae2d93a33e448d52ddeec144f	auth_user=tom
Aug 15 17:06:02 imap-login: Info: Logged in: user=<tom@example.com>, method=PLAIN, rip=172.17.0.1, lip=172.17.0.2, mpid=15, session=<Cd5NZ2o8ZpysEQAB>

examples

Other examples:

• two-userdbs
  use of two different userdbs, each both for the user and pass databases. This also shows the use of the userdb_result_failure and userdb_result_success configuration directives.
• no-domain
  use of the same userdb, both for domain-less and "with" domain logins.
• metadata
  check if imap metadata plugin is working.
• migration
  an example of migrating an older dovecot.conf to the new 2.4 syntax.

notes

To read out the default dovecot.conf from the Docker image, do something like the following:

docker run -p 1143:143 -p 1993:993 dovecot/dovecot:latest
CONT_NAME=$(docker container ls --filter="ancestor=dovecot/dovecot:latest" --format='{{.Names}}')
docker cp ${CONT_NAME}:/etc/dovecot/dovecot.conf /tmp/d.conf

The dovecot binaries are at /dovecot/bin in the container. You can use these if needed using exec, for example:

docker exec ${CONT_NAME} /dovecot/bin/doveadm config imap

The main configuration reference for Dovecot CE 2.4.x is here.

Have a look at the Dovecot testing guide.

The "Upgrading Dovecot CE from 2.3 to 2.4" docs are here and include a link to an example config for 2.4 at https://github.com/dovecot/tools/blob/main/dovecot-2.4.0-example-config.tar.gz

The configuration included with the docker image can be read by using docker container export ... which writes to a tar file.

licence

MIT